Cycles, which term is understood to include bicycles, tricycles, unicycles and other pedal-powered devices, may include shock damping devices such as shock absorbers for absorbing road shocks which would otherwise be communicated to the cycle frame. Mountain bikes and other such off-road cycles are often operated under extreme conditions in which severe road shocks are encountered. In order to maximize a rider's comfort and minimize dangers of damage to the frame of the cycle, shock damping devices are frequently incorporated into the frame of the cycle. These shock damping devices generally operate on a combination of hydraulic (including pneumatic) and spring action. These devices are frequently included in the front fork of the cycle as well as in association with the rear wheel.
While shock damping devices can function efficiently to absorb road shocks, the inherent flexibility which they provide to the frame of the cycle is at times undesirable. This flexibility presents a particular problem when a rider exerts a high degree of torque on the pedal cranks. In such instance, the flexibility of the shock dampers causes the suspension to move, producing an action referred to in the sport as “bobbing.” Bobbing is particularly notable when the cycle is being ridden under extreme conditions such as those encountered in off-road racing and other competitive events. Bobbing results in wasted energy on the part of the rider, since a portion of the rider's energy input is nonproductively absorbed by the shock damping devices.
While the inclusion of shock damping devices in cycle constructions is desirable, there is a real need to eliminate the bobbing effect produced thereby. In this regard, the prior art has implemented a number of solutions toward controlling bobbing. One approach involves the use of selectively activatable damping devices. These devices are generally controlled by a user operated lever positioned on the handlebars of the cycle. This lever allows a user to lock out the damping device when it is desirable to eliminate bobbing. The problem with devices of this type is that they require constant user input, and do not respond quickly enough to maximize shock damping while minimizing bobbing. Other control systems employ inertial devices or mechanical linkages to control the action of a damping device. These approaches are expensive, and are very difficult to implement since they require precisely machined parts and/or specially dedicated frames. In addition, devices of this type are very difficult to maintain, and must generally be tuned for each rider's weight and pedaling characteristics. Such devices are shown in U.S. Pat. Nos. 5,354,085; 6,217,049 and 6,076,845 among others.
There is a need for a control system for selectively activating the shock damping devices of a cycle, which system is simple to implement and maintain. The system should not require any extensive modification of a cycle frame, and it should be capable of being readily adapted to a variety of riders and riding conditions. As will be explained in detail hereinbelow, the present invention provides a system of this type.